Cross-Beam Energy Transfer Saturation by Ion Heating

We measure cross-beam energy transfer (CBET) saturation by ion heating in a gas-jet plasma characterized using Thomson scattering. A wavelength-tunable ultraviolet (UV) probe laser beam interacts with four intense UV pump beams to drive large-amplitude ion-acoustic waves. For the highest-intensity interactions, the power transfer to the probe laser drops, demonstrating ion-acoustic wave saturation. Over this time, the ion temperature is measured to increase by a factor of 7 during the 500-ps interaction. Particle-in-cell simulations show ion trapping and a subsequent ion heating consistent with measurements. Linear kinetic CBET models are found to agree well with the observed energy transfer when the measured plasma conditions are used.

Work-related respiratory symptoms in Champagne vineyard workers

BACKGROUND

Vineyard workers (VW) are exposed to various respiratory allergens. The aims of the study were to determine the prevalence of work related respiratory symptoms (WRS) in Champagne VW in France and to analyze the relationships between symptoms, occupational exposure and sensitization profile.

METHODS

VW of Reims area were prospectively recruited between 2007 and 2010. Demographic and occupational characteristics were recorded. Respiratory symptoms were scored for each month of the past year. Results of respiratory functional tests and skin prick tests for common respiratory allergens, grape moulds and vine pollen were recorded.

RESULTS

307 subjects were included. The prevalence of WRS was 11%. Compared to subjects with symptoms unrelated to work, subjects with WRS were more frequently sensitized to gramineae (34% vs 18%, p = 0.05), described ocular itching (74% vs 37%, p < 0.001) and seasonal symptoms (88% vs 69%, p = 0.03) mainly during lifting and trellising (57% vs 17%, p < 0.001).

CONCLUSION

WRS are frequent in Champagne WV and are associated with a sensitization to gramineae and with activities performed close to vine in late spring.

Numerical investigation of leaky modes in helical structural waveguides embedded into a solid medium

Helical multi-wire cables are widely used in bridges (suspended or prestressed) and anchored retaining wall constructions. Such structures can be damaged or degraded due to corrosion and fatigue. Non destructive evaluation techniques are required to reveal defects inside cable structures. Among these numerous techniques, elastic guided waves are of potential interest owing to their ability to propagate over long distances. However in civil engineering, cables are often buried or grouted in large solid media that can be considered as unbounded. Waves can strongly attenuate along the guide axis due to the energy leakage into the surrounding medium, which reduces the propagating distance. This energy leakage can be enhanced in helical structures, which further complicates their inspection. Searching modes with low attenuation becomes necessary. The goal of this work is to propose a numerical approach to compute modes in embedded helical structures, combining the so-called semi analytical finite element method and a radial perfectly matched layer technique. Two types of radial perfectly matched layer, centered and off-centered, are considered. Both are implemented in a twisting coordinate system which preserves translational invariance. The centered configuration is validated thanks to the twisted cylinder test case. The effect of twist on the eigenspectrum is briefly discussed. Then, an embedded helical wire of circular cross-section is considered. The off-centered configuration is shown to give the same results as the centered one. The effect of twist on modal attenuation is investigated. Finally, computations are performed for a seven-wire strand embedded into concrete, widely used in civil engineering cables.

The lupus family registry and repository

The Lupus Family Registry and Repository (LFRR) was established with the goal of assembling and distributing materials and data from families with one or more living members diagnosed with SLE, in order to address SLE genetics. In the present article, we describe the problems and solutions of the registry design and biometric data gathering; the protocols implemented to guarantee data quality and protection of participant privacy and consent; and the establishment of a local and international network of collaborators. At the same time, we illustrate how the LFRR has enabled progress in lupus genetics research, answering old scientific questions while laying out new challenges in the elucidation of the biologic mechanisms that underlie disease pathogenesis. Trained staff ascertain SLE cases, unaffected family members and population-based controls, proceeding in compliance with the relevant laws and standards; participant consent and privacy are central to the LFRR's effort. Data, DNA, serum, plasma, peripheral blood and transformed B-cell lines are collected and stored, and subject to strict quality control and safety measures. Coded data and materials derived from the registry are available for approved scientific users. The LFRR has contributed to the discovery of most of the 37 genetic associations now known to contribute to lupus through 104 publications. The LFRR contains 2618 lupus cases from 1954 pedigrees that are being studied by 76 approved users and their collaborators. The registry includes difficult to obtain populations, such as multiplex pedigrees, minority patients and affected males, and constitutes the largest collection of lupus pedigrees in the world. The LFRR is a useful resource for the discovery and characterization of genetic associations in SLE.

Identification of unique microRNA signature associated with lupus nephritis

MicroRNAs (miRNA) have emerged as an important new class of modulators of gene expression. In this study we investigated miRNA that are differentially expressed in lupus nephritis. Microarray technology was used to investigate differentially expressed miRNA in peripheral blood mononuclear cells (PBMCs) and Epstein-Barr Virus (EBV)-transformed cell lines obtained from lupus nephritis affected patients and unaffected controls. TaqMan-based stem-loop real-time polymerase chain reaction was used for validation. Microarray analysis of miRNA expressed in both African American (AA) and European American (EA) derived lupus nephritis samples revealed 29 and 50 differentially expressed miRNA, respectively, of 850 tested. There were 18 miRNA that were differentially expressed in both racial groups. When samples from both racial groups and different specimen types were considered, there were 5 primary miRNA that were differentially expressed. We have identified 5 miRNA; hsa-miR-371-5P, hsa-miR-423-5P, hsa-miR-638, hsa-miR-1224-3P and hsa-miR-663 that were differentially expressed in lupus nephritis across different racial groups and all specimen types tested. Hsa-miR-371-5P, hsa-miR-1224-3P and hsa-miR-423-5P, are reported here for the first time to be associated with lupus nephritis. Our work establishes EBV-transformed B cell lines as a useful model for the discovery of miRNA as biomarkers for SLE. Based on these findings, we postulate that these differentially expressed miRNA may be potential novel biomarkers for SLE as well as help elucidate pathogenic mechanisms of lupus nephritis. The investigation of miRNA profiles in SLE may lead to the discovery and development of novel methods to diagnosis, treat and prevent SLE.

Localization and replication of the systemic lupus erythematosus linkage signal at 4p16: interaction with 2p11, 12q24 and 19q13 in European Americans

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by both population and phenotypic heterogeneity. Our group previously identified linkage to SLE at 4p16 in European Americans (EA). In the present study we replicate this linkage effect in a new cohort of 76 EA families multiplex for SLE by model-free linkage analysis. Using densely spaced microsatellite markers in the linkage region, we have localized the potential SLE susceptibility gene(s) to be telomeric to the marker D4S2928 by haplotype construction. In addition, marker D4S394 showed marginal evidence of linkage disequilibrium with the putative disease locus by the transmission disequilibrium test and significant evidence of association using a family-based association approach as implemented in the program ASSOC. We also performed both two-point and multipoint model-based analyses to characterize the genetic model of the potential SLE susceptibility gene(s), and the lod scores both maximized under a recessive model with penetrances of 0.8. Finally, we performed a genome-wide scan of the total 153 EA pedigrees and evaluated the possibility of interaction between linkage signals at 4p16 and other regions in the genome. Fourteen regions on 11 chromosomes (1q24, 1q42, 2p11, 2q32, 3p14.2, 4p16, 5p15, 7p21, 8p22, 10q22, 12p11, 12q24, 14q12, 19q13) showed evidence of linkage, among which, signals at 2p11, 12q24 and 19q13 also showed evidence of interaction with that at 4p16. These results provide important additional information about the SLE linkage effect at 4p16 and offer a unique approach to uncovering susceptibility loci involved in complex human diseases.

Determination of soluble aluminium concentration in alkaline humic water using atomic absorption spectrophotometry

The steps of the standard method to determine soluble aluminium concentration are filtering, followed by acidifying, then analysing with the atomic absorption spectrophotometer (AAS). When applied to alkaline humic water, acidification gives rise to the formation of humic acid as a brown particulate matter. Of the total soluble aluminium in the original water, 49-61% forms complexes with the particulate humic acid upon acidification. Although the AAS is capable of detecting the binding aluminium, the particulate nature of humic acid easily induces inaccurate readings as a result of the non-uniform distribution of the particulate matter. A more precise analysis of soluble aluminium concentration of alkaline humic water is shown to be achievable in basicified solutions instead. Basicified solutions keep humic acid in the soluble form; hence maintain the homogeneity of the sample.

DNA-protein cross-linking via guanine oxidation: dependence upon protein and photosensitizer

DNA-protein cross-links form when guanine undergoes a 1-electron oxidation in a flash-quench experiment, and the importance of reactive oxygen species, protein, and photosensitizer is examined here. In these experiments, a strong oxidant produced by oxidative quenching of a DNA-bound photosensitizer generates an oxidized guanine base that reacts with protein to form the covalent adduct. These cross-links are cleaved by hot piperidine and are not the result of reactive oxygen species, since neither a hydroxyl radical scavenger (mannitol) nor oxygen affects the yield of DNA-histone cross-linking, as determined via a chloroform extraction assay. The cross-linking yield depends on protein, decreasing as histone > cytochrome c > bovine serum albumin. The yield does not depend on the cytochrome oxidation state, suggesting that reduction of the guanine radical by ferrocytochrome c does not compete effectively with cross-linking. The photosensitizer strongly influences the cross-linking yield, which decreases in the order Ru(phen)(2)dppz(2+) [phen = 1,10-phenanthroline; dppz = dipyridophenazine] > Ru(bpy)(3)(2+) [bpy = 2,2'-bipyridine] > acridine orange > ethidium, in accordance with measured oxidation potentials. A long-lived transient absorption signal for ethidium dication in poly(dG-dC) confirms that guanine oxidation is inefficient for this photosensitizer. From a polyacrylamide sequencing gel of a (32)P-labeled 40-mer, all of these photosensitizers are shown to damage guanines preferentially at the 5' G of 5'-GG-3' steps, consistent with a 1-electron oxidation. Additional examination of ethidium shows that it can generate cross-links between histone and plasmid DNA (pUC19) and that the yield depends on the quencher. Altogether, these results illustrate the versatility of the flash-quench technique as a way to generate physiologically relevant DNA-protein adducts via the oxidation of guanine and expand the scope of such cross-linking reactions to include proteins that may associate only transiently with DNA.

Sodium, potassium-activated adenosine triphosphatase activity is impaired in the guinea pig pancreatic duct system in streptozotocin-induced diabetes

In patients with type I diabetes mellitus, clinical studies have demonstrated decreased secretion of pancreatic juice by the pancreatic excretory duct system. The cause of this decrease is unknown, but could involve changes in initial signal transduction pathways or one or more of the electrolyte transport components that subserve regulated fluid secretion. We have compared responsiveness to secretin in pancreatic ducts isolated from healthy and diabetic Hartley guinea pigs and also have compared the expression of CFTR and Na+, K(+)-ATPase in these two groups, as the activities of these two proteins are essential for secretion of pancreatic juice. The increases in cyclic AMP levels evoked by exposure to either 0.1 nM or 0.1 microM secretin were not significantly different in pancreatic ducts isolated from healthy and diabetic guinea pigs nor were levels of CFTR or Na+, K(+)-ATPase expression. By contrast, Na+, K(+)-ATPase activity in pancreatic ducts isolated from diabetic guinea pigs was decreased by 70%, suggesting a change in the enzyme's catalytic properties in the diabetic tissues. The observed decrease would be expected to seriously compromise the production of pancreatic juice.

Radiographic imaging studies in pediatric chronic sinusitis

BACKGROUND

The diagnosis of chronic sinusitis is dependent on the radiographic evidence of sinus disease.

METHODS

We evaluated the performance of radiographs and computed tomographic (CT) scans for the examination of the paranasal sinuses of 91 patients of both sexes, ranging in age from 2 to 17 years, who had chronic upper respiratory tract symptoms for at least 3 months. The CT scan findings were categorized as no disease; minimal disease, and mild, moderate, and severe sinusitis.

RESULTS

Fifty-eight patients (63%) had chronic sinusitis: CT scan abnormalities were minimal in 17%, mild in 19%, moderate in 21%, and severe in 43%. There was a statistically significant correlation between rhinorrhea (r = 0.25, p = 0.01), cough (r = 0.27, p = 0.009), and the severity of sinus abnormality as determined by CT scan. Clinical presentation in the mild, moderate, and severe sinusitis groups (p < 0.05) was significantly different from that of the no disease group, whereas the minimal disease group had subclinical presentation (p = 0.11). Clinically significant chronic sinusitis often occurred at multiple sites: 44% of patients had pansinusitis, 50% had disease involvement of at least two sinuses, and 6% had disease in a single sinus. When sinus radiographs were compared with CT scans (n = 70 cases), radiographs could not identify minimal disease. For clinically significant sinusitis, sinus radiographs detected disease in 1 of 5 (20%) frontal sinuses, 0 of 12 (0%) sphenoidal sinuses, and 17 of 31 (54%) ethmoidal sinuses. With the minimal criteria of 40% to 50% opacification or fluid level filling of the maxillary antrum, radiographs detected disease in 37 of 49 (75%) cases. The sensitivity and specificity for a Waters view to confirm clinically significant chronic sinusitis without specifying the sites and severity were acceptable at 76% and 81%, respectively. When limited sinus CT scans were compared with full CT evaluation (n = 49 cases), limited studies detected 5 of 5 (100%) frontal, 9 of 11 (82%) sphenoidal, 14 of 19 (73%) ethmoidal, and 39 of 40 (97%) cases of maxillary sinusitis. The overall agreement was 88%.

CONCLUSIONS

A single Waters view is an acceptable part of the initial evaluation of pediatric chronic sinusitis; however, a limited CT scan is a better alternative.

Chronic sinusitis among pediatric patients with chronic respiratory complaints

We examined the prevalence of chronic sinusitis among children who presented to allergy clinics with chronic (> or = 3 months) respiratory symptoms. Ninety-one patients, ranging from 2 to 17 years of age with 62% male and 72% white, completed the study. Fifty-nine percent of patients had positive skin test results, and 25.3% had chronic asthma. Paranasal sinuses were examined by coronal sinus computed tomographic scan. Sixty-three percent (58 to 91) had chronic sinusitis, 5.5% (5 of 91) had concha bullosa, 1% (1 of 91) had foreign body, and 19% (19 of 91) had deviated nasal septums. Among symptoms of sneezing, nasal congestion, postnasal drip, coughing, wheezing, rhinorrhea, and headache, no single symptom was an acceptable predictor of abnormality on computed tomographic scan examinations. Combining the symptoms of moderate to severe rhinorrhea and cough with minimum sneezing had a specificity of 95% and a sensitivity of 38% in predicting the presence of chronic sinusitis. Allergic rhinitis (p = 0.27), mild deviated nasal septum (p = 0.11), unobstructive concha bullosa (p = 0.13), and passive exposure to cigarette smoke (p = 0.53) were not risk factors associated with sinus abnormalities. Age (r = 0.30, p = 0.004) in pediatric patients with chronic respiratory symptoms was the single risk factor significantly associated with abnormalities on sinus computed tomographic scan. Seventy-three percent of children 2 to 6 years of age, 74% of children 6 to 10 years of age, and 38% of children older than 10 had chronic sinusitis.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparative study of releasing and nonreleasing human basophils: nonreleasing basophils lack an early component of the signal transduction pathway that follows IgE cross-linking

Basophils from approximately one fifth of the population were found to be unresponsive (nonreleasers), in terms of both histamine and leukotriene release, to an IgE cross-linking stimulus, such as anti-IgE antibody. Although unresponsive to any IgE-mediated stimulation, these basophils responded to non-IgE-mediated stimuli, such as the phorbol ester, 12-o-tetradecanoyl phorbol-13 acetate, the calcium ionophore, A23187, and to formyl-methionyl-leucyl-phenylalanine peptide. These stimuli produced equal dose-response curves in both releaser (basophils able to respond with greater than 5% histamine release to anti-IgE antibody) and nonreleaser basophils. Nonreleaser basophils possessed statistically similar densities of cell-surface IgE antibody (287,000 versus 400,000 IgE molecules per basophil for releaser and nonreleaser basophils, respectively), and with 12-o-tetradecanoyl phorbol-13 acetate as a probe of anti-IgE-induced cross-linking, the IgE on nonreleaser basophils was found to be cross-linked by the polyclonal anti-IgE antibody used for these studies. Interleukin-3 (IL-3) has previously been demonstrated to enhance markedly both histamine and leukotriene release in human basophils. However, IL-3 was unable to convert nonreleasing basophils into releasing basophils, as measured by anti-IgE antibody. IL-3 equivalently enhanced formyl methionine peptide-induced release in both releaser and nonreleaser basophils, suggesting that the lack of an effect on anti-IgE-induced release was not due to a lack of IL-3 receptors. Although there are several possible interpretations of these data, these results and results of our previous studies of protein kinase C activation and cytosolic Ca++ elevations in human basophils suggest that nonreleasing basophils have a defect in early signal transduction, possibly involving the influx of Ca++.